xref: /openbsd-src/sys/dev/diskmap.c (revision f763167468dba5339ed4b14b7ecaca2a397ab0f6)
1 /*	$OpenBSD: diskmap.c,v 1.16 2017/09/08 05:36:52 deraadt Exp $	*/
2 
3 /*
4  * Copyright (c) 2009, 2010 Joel Sing <jsing@openbsd.org>
5  *
6  * Permission to use, copy, modify, and distribute this software for any
7  * purpose with or without fee is hereby granted, provided that the above
8  * copyright notice and this permission notice appear in all copies.
9  *
10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17  */
18 
19 /*
20  * Disk mapper.
21  */
22 
23 #include <sys/param.h>
24 #include <sys/systm.h>
25 #include <sys/device.h>
26 #include <sys/errno.h>
27 #include <sys/conf.h>
28 #include <sys/dkio.h>
29 #include <sys/disk.h>
30 #include <sys/disklabel.h>
31 #include <sys/file.h>
32 #include <sys/filedesc.h>
33 #include <sys/lock.h>
34 #include <sys/malloc.h>
35 #include <sys/namei.h>
36 #include <sys/proc.h>
37 #include <sys/vnode.h>
38 #include <sys/pledge.h>
39 #include <sys/namei.h>
40 
41 int
42 diskmapopen(dev_t dev, int flag, int fmt, struct proc *p)
43 {
44 	return 0;
45 }
46 
47 int
48 diskmapclose(dev_t dev, int flag, int fmt, struct proc *p)
49 {
50 	return 0;
51 }
52 
53 int
54 diskmapioctl(dev_t dev, u_long cmd, caddr_t addr, int flag, struct proc *p)
55 {
56 	struct dk_diskmap *dm;
57 	struct nameidata ndp;
58 	struct filedesc *fdp;
59 	struct file *fp = NULL;
60 	struct vnode *vp = NULL, *ovp;
61 	char *devname;
62 	int fd, error = EINVAL;
63 
64 	if (cmd != DIOCMAP)
65 		return EINVAL;
66 
67 	/*
68 	 * Map a request for a disk to the correct device. We should be
69 	 * supplied with either a diskname or a disklabel UID.
70 	 */
71 
72 	dm = (struct dk_diskmap *)addr;
73 	fd = dm->fd;
74 	devname = malloc(PATH_MAX, M_DEVBUF, M_WAITOK);
75 	if (copyinstr(dm->device, devname, PATH_MAX, NULL))
76 		goto invalid;
77 	if (disk_map(devname, devname, PATH_MAX, dm->flags) == 0)
78 		if (copyoutstr(devname, dm->device, PATH_MAX, NULL))
79 			goto invalid;
80 
81 	/* Attempt to open actual device. */
82 	if ((error = getvnode(p, fd, &fp)) != 0)
83 		goto invalid;
84 
85 	fdp = p->p_fd;
86 	fdplock(fdp);
87 
88 	NDINIT(&ndp, 0, 0, UIO_SYSSPACE, devname, p);
89 	ndp.ni_pledge = PLEDGE_RPATH;
90 	if ((error = vn_open(&ndp, fp->f_flag, 0)) != 0)
91 		goto bad;
92 
93 	vp = ndp.ni_vp;
94 
95 	/* Close the original vnode. */
96 	ovp = (struct vnode *)fp->f_data;
97 	if (fp->f_flag & FWRITE)
98 		ovp->v_writecount--;
99 
100 	if (ovp->v_writecount == 0) {
101 		vn_lock(ovp, LK_EXCLUSIVE | LK_RETRY, p);
102 		VOP_CLOSE(ovp, fp->f_flag, p->p_ucred, p);
103 		vput(ovp);
104 	}
105 
106 	fp->f_type = DTYPE_VNODE;
107 	fp->f_ops = &vnops;
108 	fp->f_data = (caddr_t)vp;
109 	fp->f_offset = 0;
110 	fp->f_rxfer = 0;
111 	fp->f_wxfer = 0;
112 	fp->f_seek = 0;
113 	fp->f_rbytes = 0;
114 	fp->f_wbytes = 0;
115 
116 	VOP_UNLOCK(vp, p);
117 
118 	FRELE(fp, p);
119 	fdpunlock(fdp);
120 	free(devname, M_DEVBUF, PATH_MAX);
121 
122 	return 0;
123 
124 bad:
125 	if (vp)
126 		vput(vp);
127 	if (fp)
128 		FRELE(fp, p);
129 
130 	fdpunlock(fdp);
131 
132 invalid:
133 	free(devname, M_DEVBUF, PATH_MAX);
134 
135 	return (error);
136 }
137 
138 int
139 diskmapread(dev_t dev, struct uio *uio, int flag)
140 {
141 	return ENXIO;
142 }
143 
144 int
145 diskmapwrite(dev_t dev, struct uio *uio, int flag)
146 {
147 	return ENXIO;
148 }
149